Known communication and other devices, such as MTs, PDAs, and the like, use visual displays to relay information and keyboard panels as input and operating means. In these devices, both the visual displays and the key-board panels function as light waveguides, which constitute a major feature of their operation and construction. The devices allow the use of surrounding light and/or light produced by internal light sources to illuminate their displays and keyboard panels, thus enabling the reading and writing of input/output information.
In addition, these devices are intended to be utilized with the input of audio information (speech), using ordinary microphones.